1. Field of the Invention
The present invention relates to programmable electronic displays and more particularly, to such displays wherein a plurality of illuminating devices arranged in rows and sections are selectively controlled and energized by data signals derived from a photoelectric sensing and signal producing means which translates a film image into the data signals.
2. Description of the Prior Art
Electronic displays in which messages, graphic material and alphanumeric characters are displayed have gained wide spread acceptance because such displays are very effective in attracting the attention of viewers, customers or the like. Typically, such prior displays have one or more rows of individual character displays, each of which generally exhibit any letter of the alphabet, any numeral, or certain symbols designating special purposes. By appropriate wiring and programming means, the sign or display can be made to indicate any word, message or sequence of messages.
A principal shortcoming of prior art electronic displays and signs resides in their complexity and relatively high cost. Furthermore, such prior displays are limited to a relatively small size of display such as a cathode ray tube or to the physical limitations of a projection system which is usually under one hundred inches in diagonal measurement. Although large displays are employed in film projection or cinematographic projection, screens are substantially greater with the resultant limitation of light intensity in relation to distance of projector throw as well as the size of beamed image and the interference of shadows produced by opaque objects intercepting the projection beam.
Furthermore, in most prior art displays, character information is monochromatic specifying the desired message or graphics in an alphanumeric code format. Complex decoding was required to convert this alphanumeric code into drive signals to energize the requisite display segment which produced corresponding characters or graphics. A memory capable of storing such multi-bit alphanumeric codes is required and entry of new messages, instructions or graphics necessitated coding into this format. Thus, in certain systems, it was necessary to prepare a prerecorded set of instructions necessary to enter this new data into the memory. When display of color information is required, the prior systems are extremely complex since so much more additional information is required to be included in the instructive format.
It is for the above reasons, that it is extremely difficult to convert color images, as an example, on a film strip into an identical display information on a large screen presentation. Therefore, a need has existed to employ larger screens for color graphic display requiring little space or volume and which is capable, such as in the instance of cinematographic projections, viewing the colored images in broad daylight on a large screen without the limitation of light intensity reduction.